Psst! Want my advice? Keep it to yourself

This morning, I was passed in the village street by three lads on bicycles, the sort of cut-away bike you would get on to do wheelies or other stunts. They all had the saddles very low-slung, which I suppose makes for a low centre of gravity and good balance, but the disadvantage is you can't go very fast, nor can you go uphill very well.

This morning, I was passed in the village street by three lads on bicycles, the sort of cut-away bike you would get on to do wheelies or other stunts. They all had the saddles very low-slung, which I suppose makes for a low centre of gravity and good balance, but the disadvantage is you can't go very fast, nor can you go uphill very well.

To get the best possible leverage, you have to have your saddle quite high, to get the best purchase on the pedals and the best angle on the handlebars.

You are always told the correct height for a saddle is one enabling the cyclist to touch the ground with the balls of his feet, but not with his flat feet. Looking at these boys pedal with difficulty up the sloping street, I reckoned the height of their saddles was such that their knees could have easily reached the ground. I was tempted to give them a fatherly lecture on the correct height of a saddle ("Look, lads, stop for a moment, and I shall show you where your bottoms should be"); but then I reflected that a) I would only be doing it to show off, b) they thought it was stylish to have inefficient, low-slung saddles and wouldn't listen, and c) these days, I would probably be arrested for harassment.

Passing on helpful information to people who haven't asked for it is a thankless activity. When I was in the cabaret group Instant Sunshine, all of whom were doctors except me, we would sometimes find ourselves in situations where the doctors were aware of people's medical conditions and would prefer to do nothing about it. One year, we were performing at the Edinburgh Festival and did half a day's filming for Scottish television. We met an executive there called Bell, a dynamic chap, with a ruddy complexion. To me, it looked as if he were ruddy. To the rest, it looked as if he had all sorts of heart and blood conditions.

"If he doesn't slow down or change his lifestyle, he'll be gone in a year," one of them said darkly.

We were back in Edinburgh the next year. We met one of the Scottish TV blokes. We asked how Mr Bell was.

"Haven't you heard?" he said. "He's dead. Heart attack. Great shock to everyone."

Not to my doctors, though. I once asked them if they had ever been tempted to tell a stranger what was wrong with him.

"No," said the one called Barlow. "I knew a professor once who was on a train opposite an elderly pair, and the husband had a rather unpleasant condition, thyroid I think, which had turned him into a bit of a vegetable. It was this bloke's speciality, so as they were leaving the train he said to the wife: 'I am a consultant, I think I know what's wrong with your husband, and I think I could cure it'. She turned on him and said: 'I like him very well the way he is, thanks, so keep your bloody nose out of it!' Moral: don't interfere."

The only thing I can set against this rather gloomy message is the cheering story of the American millionaire who was plagued with persistent headaches. The more money he made, the worse his headaches got. He went to all the specialists, from neurologists to osteopaths, but nobody could help. Finally, his doctor said that maybe he just needed a rest from work. "Go away," he said. "Take no work with you. Get in a car and drive south. Go to Mexico."

So the millionaire packed some clothes, got in his car and started driving south. On the first night, when he was in a hotel in Texas, he found he had left all his clean shirts behind and went into a clothes shop to buy some.

"Size 15," he told the salesman.

"You look more like a 15 1/2, or even a 16 to me," said the salesman.

"15," said the millionaire. "That's what I always get."

"OK," said the salesman. "But don't blame me if you get headaches."